Monday, May 28, 2012

Hadoop: "Format aborted" Error Message

I have recently started playing around with hadoop. I went through a bunch of tutorials and docs and installed it on a Centos 6 box. When I tried to start the namenode, it gave me an error informing that my namenode dir is not formatted. Fair enough but whenever I tried to format it, it used to get aborted. I checked all the configs, user, group, permissions and what not. I read and reread the docs to figure out if I am missing anything but no luck. Every time I got the following error:

There were no logs or messages to analyze. Every things looked in order then what was the issue?

Turned out that when the CLI asked me "Re-format filesystem in /data/namenode ? (Y or N)" I was supposed to hit upper case Y and not y. I found this quite bad and un-intuitive on developers' part that they did not implement case-insensitivity or gave out a message about hitting upper case when a lower case was entered. I just hope that this post might save someone some time.

DevOps - Insights and Tutorials

About me

I am Aditya Patawari, a DevOps consultant and trainer. I specialize in Docker and related technologies. I have production experience with Enterprise Linux, Ansible, Puppet, Nagios, Docker, Python, Cloud (AWS and Google Cloud). I am primary maintainer for fedora-dockerfiles package and have contributed to several projects in config management and container ecosystem. I have been a speaker at Flock, FUDCon, NELF, GNUnify, Rootconf, FOSSAsia, CentOS Dojo, Devopsdays, FOSDEM and have delivered talks on Puppet, Ansible, Project Atomic, Kubernetes, Git, infrastructure scalability and various other topics.
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